A177862 Irregular triangle read by rows in which row n (n>=0) is a list of the numbers of different regions into which n lines can divide the plane.

1, 2, 3, 4, 4, 6, 7, 5, 8, 9, 10, 11, 6, 10, 12, 13, 14, 15, 16, 7, 12, 15, 16, 17, 18, 19, 20, 21, 22

Offset: 0

Author

N. J. A. Sloane, Dec 18 2010

Keywords

• nonn
• tabf
• more

Examples

			Triangle begins:
  1
  2
  3  4
  4  6  7
  5  8  9 10 11
  6 10 12 13 14 15 16
  7 12 15 16 17 18 19 20 21 22
  ...
		

Links

• O. A. Ivanov, On the number of regions into which n straight lines divide the plane, Amer. Math. Monthly, 117 (2010), 881-888.

Crossrefs

A000124, A055503, and A263883 are subsequences.

Cf. A241600.

Extensions

Duplicate term 22 removed on row n=6 and example fixed by Luc Rousseau, Feb 25 2019